Aircraft jet engines typically include thrust reversers to aid in stopping the aircraft during landing. Translating sleeve thrust reversers include a number of thrust reverser cascades having rows of structural frame sections (also known as “strongbacks”) and turning vanes positioned between the frame sections for redirecting engine thrust. Thrust reverser cascades are often formed as monolithic composite parts via a labor intensive composite lay-up procedure. Such parts readily meet weight and quality requirements but are not easily adapted to innovative aerodynamic features. Thrust reverser cascades may also be formed from cast metal, but metal cascades are significantly heavier than composite cascades.
Prior art attempts to fabricate complex thrust reverser cascades of composite materials have been largely ineffective. For example, U.S. Pat. No. 5,507,143 discloses injection molded vane modules that fit into a grid of frame sections thus forming an array of repeating modules. However, the complicated interface geometries and the number of interfaces between the frame sections and the repeating modules results in excessive blockage. U.S. Pat. No. 4,852,805 discloses a thrust reverser cascade that includes injection molding over a metallic frame, which eliminates the need for handling a number of turning vanes. However, over-molding metal with thermoplastics can result in substantial thermal stresses. Other thrust reverser cascade assemblies, such as the one disclosed in U.S. Pat. No. 9,758,582, are formed by sliding turning vanes into place in a one-piece frame. Unfortunately, considerable care must be taken during this assembly process to avoid displacing adhesive paste from the mating surfaces of the turning vanes, which could result in reduced and inconsistent bonding between the turning vanes and the one-piece frame. One-piece frames also requires complicated tooling that must be extracted from the free end of the one-piece frame. Furthermore, steel tooling cannot be used to form one-piece frames because a large difference in Coefficients of Thermal Expansion (CTE) between the tooling and the one-piece frames is required for extracting the tooling from the one-piece frames. The geometry of one-piece frames prevents or hinders non-destructive inspection (NDI) and post-cure machining of various features of one-piece frames, and the overall width of one-piece frames cannot easily be increased.